It's a very standard written case interview.
I've uploaded some samples here:
(message me for a password)
The best way to prepare is the following:
- Prepare for a regular case interview - it helps a lot. Basically, prep lounge website is about it
- Practice making slides. Look for publically available MBB presentations for reference. Good books are "Pyramid Principle" and "How to make it with charts"
- Practice reading cases fast and prioritizing the information. I found useful two sources:
- Written cases you'll be able to find in google or in case books. I've seen a couple in "Vault Guide to the Case Interview" and "Insead Business Admission Test"
- Harvard cases - either buy or try to find online. You can find a couple of MIT cases here for free: https://mitsloan.mit.edu/LearningEdge/Pages/Case-Studies.aspx Unfortunately free cases don't have the prep questions.
The appropriate structure for BCG written case is (However you should check the format with the company you are applying to):
Slide 1: Context, Objective, Recommendations
Slide 2-4: Analysis (Usually 1 slide with a table, 1 slide with graphs and 1 slide with pros and cons)
Slide 5: Next steps or risks & mitigation